Going The Distance

After packing up from the grey & uninspiring, Hotel Berlina – we got our bike out of the garage, loaded it up, and headed over to the other side of the valley – to the Wild Rover’s Backpacker hostel. The idea being that we would have more fun with drunken Irish and Aussie backpackers than the guy at the front desk at the Hotel Berlina. The first hurdle came at the first hill, Alanna got out and let me drive without her weight (not a laughing matter, people) until the next bit of level ground. It’s at this point I am regretting not changing the jets. I tried to do so in Puno, but we were running late, and I couldn’t find space off the road to take the carbs apart. I thought I could risk it, get to La Paz, where there would be time and technical support (the world’s highest capital city is familiar with altitude problems). Here’s a brief explanation of what this “jets” thing is all about. If you know all about this already, move onto the next paragraph, if you will be easily terrifed / bored by this technical chat, then turn away now. The diagram below alone should be enough to send you away from this webpage forever if you are of the latter constitution.

The diagram to the left explains the operation of the Venturi principle, on which a carburettor is based. You don’t really have to understand how this works, to understand this “jets” thing. It was really just to scare off the wrong kind of reader…

The engine needs air (specifically oxygen) to mix with the fuel – for the internal combustion to work. This mixing takes place in the carburettor; and the engine is designed around a specific ratio of fuel to oxygen. When the oxygen level is depleted (at high altitude), the fuel supply needs to be constricted too, so that this ratio is maintained. You can restrict the fuel supply in the carb, by unscrewing and changing these small bolts inside the carburettor – which have thin holes running through them. Normal conditions merit a main jet size of about 0.125 mm, but in high altitude (of more than 2,000m) this should be reduced to 0.120. Which I didn’t do until the third day at altitude. Which means that on this drive over to the hostel, we were limited in power, and carrying all our stuff. And each other. So our total weight was about 800kg. Also, the streets of La Paz are a nightmare; the worst traffic I have seen in Latin America, means that most streets are rammed with carsd moving very slowly. That, and the fact that the streets are as steep as the best in San Francisco or a French Alpine town, mean that hill starts happened every couple of minutes. Now I am not a mechanic (as is probably apparent to Ural fans reading this page), but basic physics would suggest that steep hills, heavy loads, low power and high altitude would be a struggle for any machine – and especially the clutch. Again for the uninitiated amongst you, the clutch is what transfers the power from the engine to the gear-box and ultimately the back wheel. If there is not enough power (high altitude & wrong jets) and there is too much stress on the system (steep hills, heavy load) then the breaking point is the clutch.

Hence, up the third hill, the clutch starts smoking. We’re stuck in traffic, at a 35 degree incline, weighing 1450lbs. Alanna hops out (new weight, 450lbs. Just kidding…) and starts pushing. The clutch is screaming. The Bolivians are gawking. And we just managed to squeak over the crest of the hill, onto a level to roll down to the hostel and lick our smoking wounds. That night I studiously changed the jets without too much difficulty, got very drunk with some Aussie backpackers, went to bed, closed my eyes, and hoped that the bike would somehow mend itself by the morning.

We stayed at the hostel until Boxing Day, when we transferred to another hotel on the other side of town to be with our other biker friends. (by following a taxi who had the specific instructions to avoid hills) And on the 28th, we set out for the south, hoping that all was well. It wasn’t.

First up, the battery was dead. I had spent some time on Christmas eve fiddling with the jets in the dark, using the headlight to illuminate he matter. Silly. After our friend Judy helped us bump start the bike, we rolled very slowly forward. When I realised that my big foot had kicked off the supply pipe from the carburettor into the engine (which I hadn’t screwed on as tightly as I should have). While I sorted that without too much difficulty, the real trouble came when I still had no power trying to climb the hill. Alberto, a helpful passer-by and president of the La Paz Harley Davidson club, helpfully told me that the clutch was burnt out. And with that, we let everything (including my temper) cool down a bit, and took a circuitous (less-hilly) route to his brother’s mechanic’s shop  Where I filmed the following…

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